Question

Which motion map represents an object moving in uniform circular motion with the greatest tangential speed?

An illustration of a circle with four black dots on the top, bottom, left and right of the circle. Each dot has a vector toward the center of the circle and a vector tangent to the circle in a counterclockwise direction. The top and right vectors are shorter than the left and bottom vectors.

An illustration of a circle with four black dots on the top, bottom, left and right of the circle. Each dot has a vector toward the center of the circle and a vector tangent to the circle in a counterclockwise direction.

An illustration of a circle with four black dots on the top, bottom, left and right of the circle. Each dot has a vector toward the center of the circle and a vector tangent to the circle in a counterclockwise direction. The right and top vectors pointing inside the circle are shorter than the left vector. The bottom vector inside the circle is longer than the other vectors.

An illustration of a circle with four black dots on the top, bottom, left and right of the circle. Each dot has a vector toward the center of the circle and a vector tangent to the circle in a counterclockwise direction. The vectors are short.

Answer 1

The second motion map (the one where each point has identical tangential and radial arrows) — it shows equal, relatively long tangential velocity arrows around the circle.

Reason: uniform circular motion requires the tangential speed to be the same at all points (equal-length tangential arrows). The first and third maps show varying arrow lengths (not uniform), and the fourth shows short tangential arrows, so the second has the greatest tangential speed.